These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: JLA: Act of God
Badass Decay: Doug Moench obviously intended them to be an inversion, but the retrained ex-superheroes are kind of hard to take seriously in their new identities, as Linkara puts it
Linkara: (in reference to Aquman's new identity as "The Hand") You're Aquaman! You're the King of the Oceans! Two thirds of the Earth's surface belongs to you! You can call up Krakens and all manner of sea creatures, and now, you're "The Hand"!
Esoteric Happy Ending: The story tries to tell us that a new generation of heroes is about, the problems with this are that there were likely millions of innocents killed due to people losing their powers, few Superheroes getting over their problems, and Kyle Rayner, ultimately, ends up killed due to psychotic obsession. This isn't getting into the fact that many tech-based supervillains keep their powers and abilities, one new, superpowered being doesn't make the world better.
Strangled by the Red String: Superman and Wonder Woman, considering that Lois is pretty handily derailed in order to break up with Clark.
That said, both Wonder Woman and Superman undergo some fairly odd changes in behaviour and world view to come together in the way they did.
They Just Didn't Care: Doug Moench has had no experience with anybody involved with this story besides Batman, and didn't bother to actually research any of them before writing it. It shows.
They Wasted a Perfectly Good Plot: The idea of an Elseworlds story involving heroes losing their powers is an interesting idea, the possibilities were not explored that well in this story due to a very confused Aesop, as well as heroes acting like brats. Another idea that would have worked fine is working together to find out what caused the Black Light and caused them to lose their powers.
A similar story had aliens separating the Justice League into their superpowered selves and powerless human selves. The powerless human selves reacting to suddenly not having superpowers was written far more realistically and allowed for some exploration of personalities: a powerless Plastic Man returns to crime and loses his sense of humor because being Plastic Man made him a good person, Kyle Ryner goes crazy as an artist because he doesn't have a ring to visualize all the ideas in his head, a powerless Jon Jonz is fascinated at no longer being afraid of fire.
Interestingly, Marvel would do something similar with one of their "What If?" issues. However, they had a way to do it that made at least some sense in-universe. One of the main events was the "House of M" incident where it ended with Scarlet Witch decreeing "No More Mutants!" and using the massive power boost she had via some sort of chaos influx, depowered many mutants. In this What-If scenario, she isnread proclaimd "No More Power" and in this one she depowered all the heroes. There was no moping or angsting on the part of the good guys (though some Unfortunate Inplications like with Wolverine). When Red Skull came with a powerful new weapon, new Avengers risked their lives with Iron Man suits and led by Peter Parker, who broke said weapon (the Cosmic Cube.)
Wangst: Superman, Green Lantern, and many other depowered heroes suffer from this.